/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.metrics.reporter.prometheus;

import org.apache.iotdb.metrics.utils.MetricType;

import java.io.FilterWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.Map;

class PrometheusTextWriter extends FilterWriter {

    public PrometheusTextWriter(Writer out) {
        super(out);
    }

    public void writeHelp(String name) throws IOException {
        write("# HELP ");
        write(name);
        write('\n');
    }

    public void writeType(String name, MetricType type) throws IOException {
        write("# TYPE ");
        write(name);
        write(' ');
        switch (type) {
            case GAUGE:
            case AUTO_GAUGE:
                write("gauge");
                break;
            case COUNTER:
            case RATE:
                write("counter");
                break;
            case TIMER:
            case HISTOGRAM:
                write("summary");
                break;
            default:
                break;
        }
        write('\n');
    }

    public void writeSample(String name, Map<String, String> labels, Object value)
            throws IOException {
        write(name);
        if (labels.size() > 0) {
            write('{');
            for (Map.Entry<String, String> entry : labels.entrySet()) {
                write(entry.getKey());
                write("=\"");
                write(entry.getValue());
                write("\",");
            }
            write('}');
        }
        write(' ');
        write(value.toString());
        write('\n');
    }
}
